function [x_dJh_sheel_mat] = dJh_sheel_mat(x)
x_dJh_sheel_mat=[0.,0.,0.2032.*cos(x(3)).*x(12),0.,0.,0.,0.,0.,0.;0.,0.,0.2032.* ...
  sin(x(3)).*x(12),0.,0.,0.,0.,0.,0.;0.,0.,0.,0.,0.,0.,0.,0.,0.];
